Synthesis and dynamic NMR study of ketenimines derived from tert-butyl isocyanide, alkyl 2-arylamino-2-oxo-acetates, and dialkyl acetylenedicarboxylates

Abstract

The adduct produced in the reaction between tert-butyl isocyanide and dialkyl acetylenedicarboxylates was trapped by alkyl 2-arylamino-2-oxo-acetates. When the aryl group is 2-methyl-6-nitrophenyl or 2,6-di-isopropylphenyl, the product exists as two stable rotamers at room temperature as a result of restricted rotation around the Ar–N single bond. When the aryl group is 1-naphthyl or 8-quinolinyl, dynamic NMR effects are observed in the 1H NMR spectra. The calculated free-energy of activation for interconversion of the rotational isomers in 1-naphthyl and 8-quinolinyl derivatives amounts to about 99 ± 2 and 68.5 ± 2 kJ mol−1, respectively.

This is a preview of subscription content, access via your institution.

Author information

Affiliations

Authors

Rights and permissions

Reprints and Permissions

About this article

Cite this article

Yavari, I., Nasiri, F. & Djahaniani, H. Synthesis and dynamic NMR study of ketenimines derived from tert-butyl isocyanide, alkyl 2-arylamino-2-oxo-acetates, and dialkyl acetylenedicarboxylates. Mol Divers 8, 431–435 (2004). https://doi.org/10.1023/B:MODI.0000047510.22335.8c

Download citation

  • hindered rotation
  • ketenimines
  • peri-interaction
  • tert-butyl isocyanide
  • three-component reaction
  • Ugi reaction